Surface molecular imprinting and powerfully enhanced chemiluminescence emission by Cu nanoclusters/MOF composite for detection of tramadol

Abstract

Herein, a high performance chemiluminescence (CL) system is developed for the sensitive detection of tramadol. The CL reaction is based on the direct oxidation of rhodamine 6 G (R6 G) by potassium permanganate (KMnO4), producing an ultra-weak emission. It was found that copper nanoclusters encapsulated in copper-based two-dimensional metal-organic frameworks (CuNCs@CuMOF) create a tremendous enhancing effect on the observed emission. A probable mechanism was also suggested for CL emission based on the catalytic effects of nanomaterial and chemiluminescence resonance energy transfer (CRET) events. Besides, it was observed that tramadol caused a relatively selective increasing effect on the CL emission of R6 G-KMnO4-CuNCs@CuMOF system. In order to guarantee a selective response for tramadol, an extraction process using molecularly imprinted polymer modified Fe3O4@SiO2 nanoparticles (MIP-Fe3O4@SiO2 NPs) was applied before the CL analysis. The dispersed MIP-Fe3O4@SiO2 NPs showed high specificity for the extraction of tramadol from its samples. The combination between the high improved CL detection system and the efficient extraction process caused an ultrasensitive and selective determination method for tramadol. The best linear calibration graph was obtained in the concentration range of 0.0030–2.5 μM tramadol, with a detection limit (3Sb/m) of 0.80 nM. The illustrated CL method was tested for the quantification of tramadol in biological fluids, which led to the acceptable and reliable results.